High-fire glazes Glazes intended for high-fire clays are fired in the same cone and temperature range as the clay body of this category. Like stoneware, they are also dense and durable. However, the color range is limited due to the varying effects of oxidation and reduction on glaze colorants.Click to see full answer. Also asked, what does high fire clay mean?High Fire (Cone 10) Showing 1 – 24 of 31 products. A Cone rating means that you can fire that clay at any temperature up to that cone. The closer you get to the maximum rated cone, the denser and stronger your clay will be. You cannot fire a clay higher than its maximum-rated Cone, or it will melt.Secondly, what is fire clay used for? The principal uses of fire clay are in the manufacture of firebrick and of various accessory utensils, such as crucibles, saggers, retorts, and glass pots, used in the metalworking industries. Keeping this in view, what happens if you low fire high fire clay? Firing clay too high can cause it to deform or even melt, too low and it will not be durable. Firing glazes too high can cause run-off on the pot, too low and they will be dry and rough. To fire to the right temperature, pyrometric cones are used.What are the 4 main types of clay?While there are thousands of clay bodies available for purchase, the 3 basics types are porcelain, stoneware and earthenware.